Telephone-exchange system.



R. H MANSON. TELEPHONE EXCHANGE SYSTBH..

Jggsno -i APPLIOATIOH FILED FEB. 19, 1910.

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APPLICATION FILED FEB. 19, 1910 998,705. Patented July 25, 1911.

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910775935193 4 mine/7 ri=4 -Q77 Fay/i/Vansong I yZ 1 'UNE sra'rns PATENT OFFICE.

RAY H. MANSON, OF ELYIRIA, OHIO, ASSIGNOR TO THE DEAN ELECTRIC COMPANY, OF

' ELYR-IA, OHIO, A'CORPORATION OF OHIO.

TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent. Patented July 25, 1911.

Application filed February 19, 1910. Serial No. 544,734.

To all whom it may concern: 7

Be it known that I, RAYHLMnNsON, a citizen of the United States, residing at Elyria, in the county of Lorain and State of Ohio, have invented certain new and useful Improvements. in Telephone-Exchange Systems; and I do hereby declare the following to be a full, clear, and exact descriprange a telephone system having a central oflice connection means so that after. a subscriber has once'been called, the calling subscriber will beable to clear out by' merely hanging up his receiver. Both subscribers will then be able to make calls and be answered without waiting for the customary disconnect at the central ofli'ce.

A further object of my invention is to arrange in an exchange system having double supervisorylamps, an automatic disconnect circuit provided with automatic ringing so that after a predetermined time the ringing of the subscribers bell will cease and the circuit will be put in such a condition that the calling subscriber will be able. to get adisconnect without having to depend on the operators observing the flashing of the supervisory signal.

Briefly stated, the invention comprises supplementary cutoff relays inserted in the cord circuits and controlling the continuity thereof, one of said relays being a time relay. These relays are brought into service at a predetermined interval after the operator has called a subscriber who fails toanswer,

I and operate to prevent'the further ringing up of said subscriber, at the same time putting both subscribers back on their line signals so that they can make calls and be answered in the ordinary way.

My invention is illustrated in the accompanying drawings where1n F gure 1 is a diagram showing a cord circuit in a central oflice and one embodi-.

ment of my invention as applied thereto.

Fig. 2 shows the line' jack end of a subscribers line circuit. Fig. 3 is an enlarged detail view showing the operationof a thermostatic relay. Fig. 1 is a View similar to that shown in Fig. 1 illustrating a modification of the disconnect mechanism.

Referring to Fig. 1, P and P represent v the answering and calling plugs respectively of'a cord circuit. These plugs are normally connected by way offthe conductors 68 10-12 and 79'111'3, broken of course by the condensers C- and C and 8, 10 and 12, 7and 9, and 11 and 13, are inserted contacts controlled in pairs by the relay magnets D and D. The main battery B is bridged in the cord as usual, each end of the cord being typical, the bat-. tery connected to the sleeve side 9 through supervisory control relay S and to the tip side 8 through the supervisory relay S wires 19 and 21, thus forming. a bridge on one side of the condensers, and wires 20 and 22, with the corresponding relays S, S forming a similar bridge on the other side.

lVhen a subscriber takes down his receiver either in calling or answering and the respective plug is inserted in the proper jack, the relay S or S pulls up' at once, taking current from ground to battery and ground over the sleeve side, 9,72, in seri s with the cut-off relay V. This puts battery on Between 6 the .wire 32 or 33, as the case may be, and

.the lamp 8 or s is thereafter controlled by the relay S 101 S itself controlled over the tip side of line from the subscribers station.

From extra back contacts'in series, of the relays S and S I derive the circuit of my control relays D and D, which may be traced as follows :battery B, 23, f, 35, 34, 17,

'16, D, 15,- D, 14, 30 and ground. Beside the two armatures of relays S and S this circuit is controlled by' the locking 'relay F.. 'Of course the relays D, D must be normally denergized, and in order that they may cutoff the plugs I have provided an automatic device to throw said relays into circuit, and which forms the subject of the present invention. The relay F is energized through the wire 34 by the relay S battery then coming on the relay F, which pulls up and puts battery on itself to lock. In order that it shall unlock again, both plugs P, P must be in their seats, each seat being provided with the plug seat switch closed to ground, the wire 24 and relay F through the .branches 26 2-8, and 2527 when the plugs are out.

Relay A takes the place of the regular ringing key of a cord circuit. This relay is operated by means of a single contact key K which closes the circuit from the battery B through sition by the contact 39, while the relay M is energized and slowly moves its armature, this movement being controlled by the dash pot N. When the armature'of the relay M is completely drawn up, the contact 40 is closed which connects the circuit -to earth, locking the armature of this relay M in its operated position and placing a lowresistance shunt' across the winding of the relay A, thereby allowing the latter to release its armature. The relay M also operates a passing contact 41, which momentarily connects the tip and sleeve sides of the cord circuit together, thereby taking theplace of the answering .of the called subscriber. jwThis operates the tip calling relay S and through a contact 41 on the latter energizes the relay F so as to put the same in a position to complete the release circuit when the calling subscriber hangs up or moves the. hook switch.

The ringing current is furnished'by a generator 42 and passes through an interrupter 43 arranged to give any desired interruption in the ringing of the bell, such as'one second on and four seconds 011'. It will be seen that with the relay M arranged to operate in fifteen seconds that three complete interruptions of the ringing current will be had. In other words, the subscriber will be rung from two to three times and the circuit put in condition so that the calling party can get a disconnect if he so desires, after waiting a reasonable length of time for the other party to answer.

The electromagnet and the dash pot of the relay 'M can be replaced by any similarly operating mechanism, such as the thermostat shown in Fig. 3. Two strips of metal 44 and 44, having dissimilar coefiicients of expansion, are riveted together and wound with a resistance wire 45 and the latter inserted in the circuit between the points as and y in place of the relay winding. The laminated metal bar will? be gradually heated and the unequal expansion will cause it to bend slightly until a contact is made at the points 40 and 41.

In the automatic ringing circuit just describedit will be noted that a predetermined mentioned relay and the necessary connections.

Referring to Fig. 4, the ringing circuit from the generator 42 is interrupted by the interrupter 43, after which it finds a path through the condenser 46 in shunt with one wire 47 of a thermal relay T, thence to the tip side of the calling cord and to line through the closed contact 48 of the relay A. The ringing current after passing through the subscribers signal bell returns through the sleeve side of cord, contact 49, noninductive resistance 50,, battery and ground. The resistance of the signaling circuit in thesubscribers instrument is sufficiently high to prevent the ringing current from heating up thewire 47 of the thermal relay T so as to open up its contact 51. As soon as the subscriber removes his receiver 'from thehook switch, the resistance of this external circuit is greatly reduced and sufficient ringing current is allowed to flow through the circuit to heat the wire 47 of the thermal relay and open the contact 51. This breaks the locking circuit of the relay A and allows it to resume its normal posi tion..

The operation of the circuits shown in Figs. 1 and 2 is as follows: When a sub scriber calls, closing circuit through 1 and 2, therelay R takes current and'the lamp 4 lights. a The plug P is inserted and the number obtained. When the plug P is inserted,

the cut-off circuit is completed through the sleeve side of the cord as follows: ground sideof battery, B, S, 21, 9, 7, p, 3, V, ground. .V pulls up and the line lamp 4 is extinguished. The relay -S pulls up and puts battery on wire 32, lighting the lamp 8. Circuit 12 beingclosed at the substation, current flows over the path already traced and as the relay V has pulled up, the cur rent continues through=21, j, p, 6, 8, 19,-S 31, ground. Relay S pulls'up, extinguishing lamp 8 and breaks the circuit of the, relays D, F and D. The line wanted is now tested, the plug P inserted and the operator presses the ringing key K. As before stated, the circuit is now closed from battery B through (l, 37, M, 38, A, K, and ground. The relay A is operated and locked through 39, the ringing current now passing at intervals through the closed contacts 48 out on the line, and through the signal bell of the called subscriber. The relay M, in the meantime, has been slowly pulling up, and

.if the called subscriber has not answered,

the passing contact 41 momentarily connects the tip and sleeve sides of the cord circuit together, thereby taking the place of the answering subscriber. This momentarily operates the relay S and the latter closes a I circuit and'energizes relay F, which pulls up and-locks. When the armature ofthe relay M is completely drawn up, it is locked and the relay A lets go, its winding being shunted to earth through the Contact of the relay M. Having been unable to get the Iparty wanted, the call ng subscriber now angs up his receiver or moves his hook switch. The linecircuit is broken and the armature of the relay S? falls. back thereby establishing the following circuit: 31, B, 23, f, .35, 34, 17, 16, D, 15, D, 14, 30. Both relays D and D then pull up, cutting off the plugs from the rest of the circuit. These bare plug ends, which are harmless, may be left in the jacks Without effecting the line in any way. 'The .cut-oif relays V put both subscribers back on their line relays R and they can make calls as before. When the operator gets ready to disconnect, she takes down the plugs P and P and their restoration to their seats opens the switches. 27 and 28, thereby breaking the circuit through the locking relay F which lets go, and battery is at once taken off the wire 34, and hence oil the relays D and I). These relaysretract and the cord circuit is again complete and. ready for another operation.

In Fig. 4 the operation is the same as in Fig. 2, except that in this case if the called subscriber should answer before the relay M had fully pulled up, the closing of the circuit at the hook switch so reduces the external resistance of the circuit that enough of theringing current from the generator- 42 will go through the thermal relay T to actuate the latter, thereby breaking the locking circuit of the relay'A and hence disconnecting the generator 42 from the line. After therelay A has released, the cord circuit may be broken by either subscriber hanging up his receiver or moving his book switch, the cut-off relays D and D effecting this operation in the same manner as previously described.

My invention provides asimple and positive means for disconnecting the cord circuit after the automatic ringing has ceased, and for putting the subscribers back on their line signals, without waiting for the operator to disconnect the cord plugs which she would ordinarily have to do before a new connection could be obtained.

lVhile I have shown this particular form of my invention and have shown it applied to this particular form of circuit, it will be obvious-to those skilled in the art to which this invention appertains, that numerous and extensive departures from' the form and I the details of the apparatus here shown .circuit therefor, means operated by the calling subscriber for disconnecting the cord plugs from the main cord circuits, and means operating onthe completion of the ringing, to place the cord circuit in condition to be thus disconnected.

2. In a telephone exchangesystem, subscribers lines, and an operators circuit for interconnecting them, with an automatic ringing circuit therefor, line signals connected with said subscribers lines, means operated by both subscribers for disconnecting the cord plugs from the main cord circuits, and means operating on completion of the ringing to place the cord circuit in condition to be thus'disconnected.

3. In a telephone'exchange system, subscribers lines, and an operators cord circuit for interconnecting-them, with an automatic ringing circuit therefor, line signals con nected with said subscribers lines, cut-off relays adapted to be operated by the calling.

subscriber for disconnecting the cord plugs from the main cord circuits, means operating on' completion of the ringing to place the cord circuit in condition to be thus disconnected, and means controlled by the op-' erator upon withdrawal of the cord plugs to break the cut-off relay circuit thereby restoring thecord to operative condition.

4. In a telephone exchange system, subscriloers lines'and an operators cord circuit havmg terminal plugs for interconnecting the lines, a supervisory signal magnet associated with each plug and controlled during connection by the corresponding subscriber, a cut-off relay'associated with each plug and adapted'when operated to disconnect the respective plug fromthe cord circuit,

' automatic ringing mechanism for said cord circuit, and means operating on completion of the ringing to place the cord circuit in condition to be disconnected.

In a telephone exchange system, subscribers lines provided with line signals, a

cord circuit comprising automatic ringing means, a time relay, cut-off relays for disconnecting the cord plugs from the cord circui't, said relays being controlled by the connected subscribers, and means actuated by said time relay for disconnecting the ring- &

ing means from the line-after a predetermined interval and for placing the cord cir- Y rupter, cut-ofi' relays'for disconnecting the plugs from the cord circuit adapted to be operated by the connected subscribers, a slow acting time relay adapted to limit the number of calls of said ringing means and arrangedto place said out-oil relays in operative connection, said time relay comprising a magnet, armatures -therefor,*and a dash pot controlling the movement of the latter, and means controlled by the operator, upon Withdrawal of-the plugs, to break the cut-off relay circuit and to restore the cord to operative condition.

7. In a telephone exchange system, subscribers lines, and a cord circuit interconnecting the lines, automatic ringing means connected with the cord circuit, means operated by the called subscriber for disconnecting the said ringing means from the line, cu't-ofi relays for disconnecting the plugs from'the cord, circuit adapted to be operated by the connected subscribers, a slow acting time relay arranged to place said cut off relays in operative connection, and means controlled by the operator upon the withdrawal of the plugs to break the cut-off relay circuit and to restore the cord to operative condition.

8. In a telephone exchange system, subscribers lines, and a cord circuit intercom necting the lines, automatic ringing means connected With the cord circuit, a thermal relay adapted to be energized by the called subscriber for disconnecting said ringing means from the line, cut-off relays for disconnecting the plugs from the cord circuit adapted to be operated by the connected subscribers, a slow acting time relay arranged to place said cut-0E relays in operative connection, and means controlled by the op-.

erator upon withdrawal of the plugs, to break the cut-off relay circuit and to restore the cord to operative condition.

9. In a telephone exchange system, sub-' scribers lines, an operators cord circuit for interconnecting said lines, said cord circuit including automatic ringing means, disconnect mechanism operating to disconneet the ringing mechanism from the line on the answering of the called subscriber, cut-off relays included in said cord circuit and arranged to be operated when the connected subscribers hang up their receivers to disconnect the cord plugs from the cord circuit, and means controlled by the operator upon .the withdrawal of the plugs to break the cut-ofi relay circuit and to restore the cordto operative condition.

10. -In a telephone system, subscribers lines, manually operated means at the centhrough the. operation of said automatic ringing devices to place said interconnecting means in condition to be broken by the calling subscriber. I

12. In a" telephone system, subscriber s lines, central officemeans for interconnecting said lines, automatic ringing devices,

and means actuated either by the operation of said ringing devices or by the called subscriber for placing said interconnecting means in condition to be broken by the calling subscriber.

13. In a telephone system, subscribers lines, manually operated means at the cell;-

tral otfice for interconnecting said lines,'automatic ringing devices, andmeans actuated in' the operation of said ringing devices to place the circuits in condition to be broken by the connected subscribers after the ringing ceases.

14. In a telephone exchange system, subscribers lines, means under the control of operators for interconnecting the lines, and means controlled first by both subscribers and then after a certain interval by only one subscriber for severing the operators con necting means.

15. In a telephone system, subscribers lines, manually operated'means at the central oflice for'interconnecti'ng said lines at one point, automatic ringing devices, and means acting to enable the calling subscriber to break said interconnecting means at another point, either on completionof the hung up his receiver.

16. In a telephone system, subscribers lines, manually operated means at the central oflice forinterconnect-ing said lines at certain points, automatic ringing devices, and means acting toplace the circuits in condition for the connected subscribers to break said interconnecting means at other points after the ringing ceases.

v17. In a telephone exchange system, subscribers lines, means for interconnecting the' lines at an exchange, means for applying ringing current to the nterconnecting means, a normally disabled means for sever- .ringing or after the'called subscriber has ing such interconnecting means, and means only under the controlof the called subscriber during the ringing condition for removing the' disability of the severing means.

18. In a telephone exchange system, submoving the disability of the seyering means,

the termination of the sending of ringing current also adapted to remove such disability.

15). In scribers a telephone exchange system, sublines, means for interconnecting the. lines at an exchange, means for applying ringing current to the iliter-connecting means, a normally disabled means for severing such interconnecting means, and means only under the control of the called subscriberduring the ringing-condition for removing the disability of the severing means, such severing means adapted to be controlled jointly by both subscribers after the response of the called subscriber:

In a telephone exchange system, subscribers lines, means for interconnecting the lines at an exchange, means for applying ringing current- .to the interconnecting means, a normally disabled means for severing such interconnecting means, and means only under the control of the called sub scriber during the ringing condition for removing the disability of the severing means, the terl'nination of the sending of ringii'ig current also adapted to remove such disability, such severing means adapted to be controlled by the calling subscriber after the termination of the sending of ringing current in the absence of response of the called subscriber.

21. In a'telephone exchange system, subscribers lines, means for interconnecting the lines at an exchange, means for applying ringing current to the interconnecting means,'and a normally disabled means for severing such interconnecting means, the termination of the sending of ringing current adapted to remove such disability, and such severing means adapted to be con trolled by the calling subscriber after the termination of the sending of ringing current in the absence of response of the called subscriber.

In testimony whereof I atfix my signature in presence of two witnesses.

\ RAY H. MANSON.

Witnesses MARY hlALLEY, F. O. RIcHnY. 

